Apparatus for making metal panels



Feb. 13, 1962 Filed Dec. 16, 1957 Plus-I 1 W. l. BALLENTINE, JR., ETAL APPARATUS FOR MAKING METAL PANELS 2 Sheets-Sheet 1 Feb. 13, 1962 w. l. BALLENTINE, JR., ETAL 3,020,867

APPARATUS FOR MAKING METAL PANELS 2 SheetsSheet 2 Filed Dec. 16, 1957 INVENTORS WILL/AM .l'. BALLENTl/VE and JAMES W MOLDE/V $77 M%/m, y

3 that to which the tension in sheet 32 tends to draw them on cooling after it has been heated and welded thereto. The extent of precambering which is desirable may be readily determined by experiment. The precambered posts 19 are drawn down, within their elastic limit, so as to bear tightly against the upper flanges of beams 12, by operating clamps 20. Rails and 16 are similarly drawn down against their supporting bars 13 and 14 by conventional C-clamps. When the panel-frame members have been thus assembled, they are welded together along their abutting surfaces.

Sheet 32 is next placed on the resulting panel frame and tray 23, and platen 37 is lowered thereon. Jacks 24 are then operated to raise the box and lift the sheet out of contact with the panel frame. Lamps 36 are then turned on and the sheet is heated thereby to a temperature between 250 and 350 F., preferably about 300 F. The thermal-insulation board 39 limits loss of heat from the sheet and therefore shortens the heating period. When the sheet has reached the desired final temperature, jacks 24 are again operated to lower the tray and bring the sheet edges into contact with the panel-frame members. The sheet is then Welded to the panel frame as quickly as possible, preferably by submerged-arc welding. The welding should be completed while the sheet is still at elevated temperature, say 275 F. To this end, energization of the heat lamps is continued during welding. On completing the welding, the lamps are turned off. Thereafter, on cooling to atmospheric temperature, the contraction of the sheet sets up internal tension therein sutficient to pull it drum-tight and overcome the bowing tendency of the frame members introduced by precambering, when they are unclamped. The platen is then removed and the panel is complete.

It will be apparent from the foregoing that our method involves heating the sheet while supporting it out of contact with the panel frame, thereby extending slightly its length and width, then welding it to the frame. After the sheet has been welded to the frame in expanded condition, the subsequent contraction on cooling effectively tensions the sheet. Such tension as results would cause bowing of the frame members in the absence of the contra-bowing tendency introduced by the precambering.

It will be further apparent that our apparatus is simple to construct and easy to operate. It may readily be fabricated in multiple units arranged side-by-side, if it be desired to fabricate a large panel such as a car door, car side or building wall. All parts of the panel are rigidly held in properly assembled relation during the welding operation, following heating of the sheet in uplifted position.

Although we have disclosed herein the preferred embodiment of our invention, we intend to cover as well any change or modification therein which may be made without departing from the spirit and scope of the invention.

We claim:

1. Apparatus for making metal panels comprising a horizontal frame including a polygonal assembly of connected structural members adapted, respectively, to support the rails of a panel frame, a heating tray including a plurality of spaced sheet supports, slidable vertically within said first-mentioned frame, and means mounted in said tray for heating a sheet disposed on said sup ports prior to being secured to said rails.

2. Apparatus as described in claim 1, characterized by said first-mentioned frame including spaced beams, each beam having a gauge bar extending therealong for positioning a panel-frame rail.

3. Apparatus as described in claim 2, characterized by gauge screws spaced along said bars.

4. Apparatus as described in claim 1, characterized by said first-mentioned frame including spaced beams, each beam having a plurality of clamps spaced therealong adapted to engage a panel-frame rail disposed thereon.

5. Apparatus as described in claim 1, characterized by rails suspended below said tray and said heating means being mounted on said rails and extending upwardly into said tray.

6. Apparatus as described in claim 1, characterized by said tray including spaced parallel partitions and said sheet supports being lugs projecting upwardly from said partitions.

7. Apparatus as described in claim 1, characterized by hydraulic jacks adjacent the ends of said first-mentioned frame, effective to raise and lower said tray.

8. Apparatus for fabricating metal panels including a frame and a covering sheet, said apparatus comprising an assembly of structural members for supporting the panel frame in a horizontal plane, a tray having a plurality of spaced lugs upstanding therefrom for supporting a sheet in panel-forming relation to a panel frame on said members, said tray fitting within said assembly and slidable vertically therein, heating means spaced longitudinally and transversely of said tray, and a weighted thermally insulated platen adapted to be placed on a sheet resting on said lugs, to hold it flat while being heated.

9. Apparatus as described in claim 8, characterized by said tray including a horizontally disposed bottom plate mounted for vertical movement relative to said members.

10. Apparatus as described in claim 9, characterized by means suspended below said plate supporting said heating means.

11. Apparatus as described in claim 8, characterized by clamps for clamping the panel frame to said members.

12. Apparatus as described in claim 8, characterized by a grid of intersecting partitions in said tray, said lugs being formed on said partitions.

13. Apparatus as described in claim 8, characterized by said frame-supporting members including a pair of spaced parallel beams, each having an upstanding gauge bar thereon adapted to fix the position of a panel-frame member.

References Cited in the file of this patent UNITED STATES PATENTS 1,774,996 Rohrmann et al Sept. 2, 1930 2,046,115 Gottlieb June 30, 1936 2,110,752 Wright Mar. 8, 1938 2,402,631 Hull June 25, 1946 2,441,858 Watter May 18, 1948 2,446,148 Weightman June 27, 1948 2,451,783 Sweeney Oct. 19, 1948 2,457,845 Strickland Jan. 4, 1949 2,537,350 Hunt Jan. 9, 1951 2,768,597 Smith Oct. 30, 1956 

